Graduated circle for radio direction finders



Aug. 8, 1933; A LElB 1,921,234

GRADUATED CIRCLE FOR RADIO DIRECTION FINDERS Filed July 22', 1929 2 Sheets-Sheet 1 NVENTOR AUGUST LEIB ATTORN EY Aug. 8, 1933. LE|B 1,921,234

GRADUATED CIRCLE FOR RADI O DIRECTION FINDERS Filed July 22, 1929 2 Sheets-Sheet 2 AUGUST ATTOR N EY V rectediby'nieans ofta'bulationsfor graphs. For

Y 1:; i such a Way thattheir abscissa axis is a "Patented Au s, 1933 funken Gesellschaft fiir Drahtlose Teleg raphie,. m b. Ii, Berlin, Germany ..1

- Application July 22, 1929, Serial No; 380,169, and in Germany August 4, 1928 :2 Claims. (or. 2 -115 7 kn wnithatthe readings taken of bear a direction finder circuitmust be corvery'anglethus read, a corrective value must be foundinand applied from the table or graph to 'thebearing'r'eadmg. This requires the expenditureof acertain'time, and this time is to be saved according tothejpresentinvention. The corrective valiies, according tothis'invention, are indidatedfupon the direc'tionfinding dial in graphic 0 e'con'centric'with, or coinciding with, the difeititinfindingcircle, while-the radial rays orlinesjbprresponding to the scales serve as the ordinates. f ,f I

The invention {will be better understood by reference to the annexed drawings in which Fig. 1

shows a radio compass arranged in accordance withmyinvention; g Q 7 Fig. lashows an enlarged detail of Fig.1; Fig. 2 shows a modification of Fig. 1, while, Fig. 2a shows in an enlarged view a detail of the arrangement of Fig. 2.

.Referring to Fig. 1, a is the graduated circle having afixed position with reference to the hull ii of the ship, its graduation between Oand 180 degrees corresponds to the midship or median line (0 at the bowand 180 degrees at the stern).

.b is the direction finding wheel which is connected with the directional element of the radio direction finder, and which carries a pointer c serving for reading bearings. d is a reading border of'the graduated circle.

The circle e being concentric thereto serves as the abscissa, and the radially, extending rays or lines 9 serve as the ordinates for the correction curves 1 and h.

Fig. 1a for the sake of greater clearness illustrates a partof the graduated bearing circle drawn to an enlarged scale.

Now, if the angle read in the direction-finder is =q and the necessary correction =1, theII the correct bearing is p=q+f. If the correct bearing f is to be ascertained merely from the uncorrected reading taken on the direction finder q, then the use of a curve, say, 1 will suf-' I fice. If in taking bearings, the pointer c is positioned on' the corresponding division q of the bearing scale or circle, then the ray or line Q being in its direction intersects on the corrective ;curve the requisite corrective ordinate f.- If

the curve I falls inside the abscissa circle, then the sense of correction is, for instance, negative,

otherwise it is positive. At, any rate, both read- 1 ings 11: result in the accurate bearing L I But if fora definite course of the vessel p the corresponding radio bearing 'q' is, to be ascercurves concentrically, intersecting with the rays r n h Theabscissa circle e'could "also be madefconcentric with the reading border d of the"graduated circle. In this case each of the curves, say, curve 7 is plotted or traced in such a way; that both for positive as well as for negative corrections it comes to fall entirely inside or outside the abscissa circle, according to whether the inner or outer edge of the graduated circle is needed forreading. But the positive or negative sense of the correctionsmust then be made-'dis tinguishable by different ways of tracing. For instance, the sections resulting in negative values could be plotted 4in red color, and the sections giving positive values in green color.

An arrangement of the kind here disclosed could be further improved so that all calculation is saved by that the reading edge of the graduated or bearing circleis used as the abscissa circle of the correction curve, and that over the graduated circle with the correction curves there is used an indicator hand drawn upon transparent material whence two line systems (say, circular systems) extend in both directions which are characterized or distinguished as regards the sign of correction in agreement with the respective sections of the corrective curve. v

Fig. 2 illustrates by way of example an embodiment of this idea. The bearingscale is plotted upon the inner edge d of the bearing dial a. The circle (1 serves at the same time as abscissa circleof the corrective curve fl For the latter,

upon the transparent plate s two line systems v (here; for instance, ciicnlar systems). Theone- V onth'e'left-hand sidel jc orresponds tqhegative 1 r is effected 'in this manner thatflthe'rordinatefot e curve I whichis out on between the reading edge enlarged scale in'Fig. 20., v e 1 Now, the'reading' of the'correct bearing angle Y corrections,- and is drawn redlllgesections l and l 3,,whi1e the right-hand one 1' corresponds @150 ordinated' to sections 2'and 4 of the .corr'efction curves. F a

' Part orthe arrangement which comprises the plateplece VS withdndieator handc is illustrated again for the sake of jgreater clearnes s to= an 4'and the'correction curve I upon the indieato'r line 051s. projectedrby' the oorre'spondin'gline ot the. n or 1 system in the correct senseuponthe reading-scale; For instance in case the indicator of the eorrection curve (indieatingf-pos'itiye cor: ctii It ls l ecommendable to ppovidefinside the .dl-

relation-finder .dial of disk a hich mm pase j has the shape of a eil eulargring') I a. movable oom- 7 pass mm m to repi oduce the" movements 01 the I eompass' needle; Th ef graduated scale of this 7 efnclels arrangediat it's ircumfeiential. edge that "is" to say, opposite thbaring sc'a1e.edge d'. It is then possible to read not only the :correct bear ing .angle im relation to the mldship (median) 1,921,234 ingln retel enoeto the compass on'th'e com-f :pass scale n; i I positive corrections; it is drawn green andls ;co- '7 1 'pointing'ermrs comprismggabearingfoirele, Tl

rection-curr es plotted on said-pearlng clicle;-;a

wh h erv he ahscis r O -t 'w': ,e ti'on eilrves whieh'farie plotted 1 thereon,--.bearlns 7' 7 adjacent the reading" edge of said 'beafinzfch'cle, ai i tence' -ensue transparent d afplur'ality of linesterminating at 1 a point adjacent-said reading cix cle,;fsald lines linec in taking bearings is over the gfeen'sec'tlon} 1 e 20 ns); then the s+system whibh ls'alsotracedgreen 1 Ito be iised That circle-o1 the r'-'system is then employed which'pas'ses through the iio'int; V. 01 interseetionof c and ,f, and one i follows this j eir'jole aa'sfaf as its pointof interseetion with the readingedge d, and thelatterlgives the correet' rmr j b in i'thefab' scissa circletoi theeorreetloni are plotted 'thQ e m'beafihK line on the scale d, the angleof the v Iolalm: f ,7 7 15A correctionj ehart 'to'ibe tional radio apparatus lnherentlyt to ,xeading 1 edge or immersio 3am cum? I read ng" means edaptedgtorbejmoved over the compris n transparent material havingean beingfintersected "by; reference 3 .3; A jcox p'ection be used wlth t mm m i vs smlnh m ismi bearing cix ole,"

crib order onsaidwe me 

